There are two basic styles of reply envelopes available, top opening
and side opening. Each style has different variations. Shown below are the basic
styles and some of their variations.

Top Opening Reply Envelopes

Top opening reply envelopes are more like a traditional envelope
and are easier for the recipient to insert their remittance. The top
opening reply envelope can be an insert in the mailer or it can be
constructed so that the last part of the outgoing mailer is used as
the back of the reply envelope.

The top opening reply envelope can be collated into the mailer just
as an insert is collated. Two parts are glued together along three
edges, leaving the top edge unglued as the opening of the envelope.
An area between envelopes is die cut out so that the outgoing envelope
can be glued together. The reply envelope is also glued into one of
the stubs that will be removed by the recipient when opening the mailer.
The reply envelope will have two flaps. During the collating process,
the seal flap will have a remoistenable adhesive applied. The other
flap is a waste flap and will have to be detached by the recipient.

Top Opening - Insert Reply Envelope

The reply envelope can also be constructed, die cut
and then inserted as a loose insert into the mailer. It is inserted
on top of the last part of the outgoing mailer at the collator and
held in place when the preceding part is collated on top of it. This
type of inserted envelope helps to reduce the thickness and stiffness
of the stub by eliminating two parts and two glue lines in the stub.
The reply envelope may or may not have a waste flap, depending on
how the envelope is constructed.

Another type of top opening reply envelope is one where
one part of it is constructed from the last part of the mailer. The
part preceding the last part of the mailer makes up the other part
of the reply envelope. It is glued to the last part along three edges,
forming a pocket with the top edge lightly spot glued to seal the
mailer on all edges. The other parts are spot glued at the top and
bottom to the reply envelope so that they can be easily peeled off,
leaving the envelope for mailing back the remittance. The spot glue
between the two flaps is carefully broken and the back flap is removed.
Using the last part of the mailer as the back of the reply envelope
reduces the thickness of the mailer by eliminating one part.

Top Opening Envelope - Last Part of Mailer
as the Back of the Reply Envelope

If a top opening envelope has a waste flap, it needs
to be detached before the envelope can be sealed. There is a feature
available where the waste flap is pulled off when the mailer is opened
by the recipient. The waste flap of the envelope is glued to the last
part of the mailer or the part preceding the envelope, depending on
which flap is the waste flap. As the mailer is peeled apart or a tab
opening is pulled open, the waste flap is detached.

Side Opening Reply Envelopes

The side opening reply envelope is available in basically
the same variety of types as the top opening envelopes. They are available
as a collated insert envelope, a loose inserted envelope and one that
has one part of it constructed from the last part of the outgoing
mailer. The side opening envelopes are also glued in pocket form along
three edges, leaving one side open. The side opening envelope is less
popular with the recipient because it is harder, than the top opening
envelope, to insert the remittance to send back.

The adhesive used for the seal flap can be remoistenable
glue or pressure sensitive tape. Pressure sensitive tape cannot be
used on the top opening envelope because it cannot be applied across
the web. On side opening envelopes it is applied parallel to the web
at the collator. Whether remoistenable glue or pressure sensitive
tape is used for sealing the reply envelope will depend on personal
preference and the manufacturers capabilities. Pressure sensitive
tape is generally less expensive than remoistenable glue for custom
short run mailers due to less make ready time but more expensive on
longer runs because of material cost.

The side opening envelope can be constructed from parts
of the mailer in the same manner as the top sealing envelope shown
above. It can also be an inserted envelope that is manufactured separate
from the rest of the mailer and then inserted in the proper location
when the mailer is collated. It does not generally have a waste flap.
The part of the envelope that does not have the seal flap is ran shorter
than the part with the flap, eliminating the waste flap.

Side Opening - Loose Inserted Envelope

An open side reply envelope is available as a reusable
mailer envelope. The mailer is sent out with a short part on the face
of the mailer that is spot glued along three edges and line glued
along the outside edge with a fugitive type glue. The short part is
imprinted with the delivery address and when the recipient receives
the mailer, they peel off the short part and discard it. The fugitive
glue allows the short part to be removed without destroying the envelope
in that area. Once the short part is removed, the return address and
the flap to the reply envelope are revealed and the insert can be
extracted. The remittance is placed back into the mailer envelope
and the flap is folded over and sealed. The mailer is then used as
the reply envelope.

Open Side - Reusable Mailer Envelope

Another style of a reusable mailer is one that has a
perforation running parallel with the left and right sides, forming
a stub on the face of the mailer. When the recipient receives the
mailer, the stub is detached at the perforation and carefully peeled
off. Detaching the stub opens the mailer and reveals the insert. The
insert is removed and the remittance is place back in the mailer where
the insert was. When the stub was removed from the face of the mailer
it also exposed the seal flap of the reply envelope. The flap is wider
than a normal flap and when folded over, it covers the outgoing delivery
address. The remittance address has been preprinted on the reply envelope
for return delivery.

Each of the different types of reply envelopes
may have slight variations in them. The differences will depend
on the manufacturer's capabilities.